CN116155779A

CN116155779A - Method and system for detecting delay time of video monitoring system

Info

Publication number: CN116155779A
Application number: CN202310416733.2A
Authority: CN
Inventors: 方彤; 庄德玉; 邱锦波; 胡涛; 郑立波; 汤子麟; 朱宏强; 张涛; 郭岱; 贺新星
Original assignee: Changshu Tiandi Coal Mining Equipment Co ltd; Tiandi Shanghai Mining Equipment Technology Co Ltd
Current assignee: Changshu Tiandi Coal Mining Equipment Co ltd; Tiandi Shanghai Mining Equipment Technology Co Ltd
Priority date: 2023-04-18
Filing date: 2023-04-18
Publication date: 2023-05-23
Anticipated expiration: 2043-04-18
Also published as: CN116155779B

Abstract

The invention provides a method and a system for detecting delay time of a video monitoring system, wherein the method comprises the following steps: the method comprises the steps that a display area of a display device of a video monitoring system to be detected and a video acquisition scene of a video acquisition device of the video monitoring system to be detected are arranged in an image framing range of an image grabbing device; video acquisition is carried out on a video acquisition scene comprising an entity timer by a video acquisition device, and a single-frame image comprising a first time mark value presented by the entity timer exists in the acquired video; when a single-frame image including a first time mark value appears in a video displayed by a display device, determining a second time mark value presented by an entity timer at the same moment in an image framing range through an image capturing device; and determining the delay time length of the video monitoring system to be detected when performing image processing based on the difference value of the second time mark value and the first time mark value.

Description

Method and system for detecting delay time of video monitoring system

Technical Field

The present invention relates to the field of video monitoring technology, and more particularly, to a method and system for detecting a delay time of a video monitoring system, a computer-readable storage medium, and an electronic device.

Background

Currently, video monitoring technology is often applied to acquiring images of an image capturing device in real time, so as to help related personnel or equipment observe, monitor and record specific scenes, conditions, features and the like of a captured space-time. The smaller the delay time of the video monitoring system is, the faster the response speed of a user when monitoring or image processing is performed by using the video monitoring system.

In the technical scheme for detecting the delay time of a video monitoring system in the prior art, the delay time is determined through message recording between a video shooting point and a video display point. For example, the delay time is determined by processing the acquisition time of the transmitting side and the display time of the receiving side. However, this approach fails to determine the exact acquisition time and display time, which in turn leads to inaccurate results in determining the delay time. In another embodiment, a time message is inserted into the image frame structure, but the time message itself also affects the content transmission of the image capturing device, which further increases the delay time of the video monitoring system and increases the amount of data transmitted.

Disclosure of Invention

In order to solve the problems in the prior art, the invention realizes better image delay time detection through the accurate time service system and the synchronous acquisition system. The clock source of the precise time service system is an active or passive clock provided by a crystal with a certain stable periodic oscillation or a precise time service device such as a Global Positioning System (GPS) or a Beidou system (BD). Frequency locking is achieved through a phase-locked loop and a voltage-controlled oscillator, and output frequency signals are counted and detected through a counter so as to output accurate time. And obtaining the time corresponding to different frequencies by calculating the timing period. Furthermore, the counting of the periods with different frequencies can meet the numerical value acquisition requirements of different photoelectric counters, so that the following accurate time is obtained.

The synchronous acquisition system arranges the time display device in the same time space, performs image recording on the time-space images currently comprising the time display device by utilizing the to-be-tested camera device, performs image recording on the images of the to-be-tested camera device and the time space displayed by the time-space real-time by utilizing the non-tested camera device, and determines the delay time by the time difference between the high-precision image or video acquisition time and the image or video display time.

According to one aspect of the present invention, there is provided a method for detecting a delay time of a video monitoring system, the method comprising:

in response to receiving a delay time detection request from user equipment, resolving the delay time detection request to obtain a region identifier and a system identifier, determining a target region in a plurality of regions based on the region identifier, and determining a video monitoring system to be detected in a plurality of video monitoring systems in the target region based on the system identifier;

the display area of the display device of the video monitoring system to be detected and the video acquisition scene of the video acquisition device of the video monitoring system to be detected are arranged in the image view-finding range of the image capturing device, wherein the video acquisition scene of the video acquisition device comprises a preset physical timer;

video acquisition is carried out on a video acquisition scene comprising the entity timer by the video acquisition device, and a single-frame image comprising a first time mark value presented by the entity timer exists in the acquired video;

transmitting the acquired video to the display device through a network transmission device of the video monitoring system to be detected, so that the display device displays the video received through the network transmission device;

When a single-frame image comprising the first time mark value appears in the video displayed by the display device, determining a second time mark value presented by an entity timer in the image framing range at the same time through the image capturing device; and

and determining the delay time length of the video monitoring system to be detected when performing image processing based on the difference value of the second time mark value and the first time mark value.

According to one example, the physical timer is an accurately recordable time generator or a fixed frequency counter.

According to one example, the image capturing device is capable of recording dynamic images of the display device and physical timer at the same time and within the view of the image.

According to one example, the image capturing device is a camera, a video camera, a mobile phone capable of moving image capturing, or a personal computer capable of moving image capturing.

According to one example, when the video displayed by the display device appears a single frame image including the first time stamp value, determining, by the image capturing device, a second time stamp value presented by an entity timer in the image view range at the same time, includes:

When a single frame image including a first time mark value presented by the entity timer appears in a display area of the display device in a dynamic image recorded by the image capturing device, determining that the current time value of the entity timer is at the same moment and within an image framing range of the image capturing device;

and determining the current time value of the entity timer as a second time mark value.

According to one example, the method further comprises the steps of respectively acquiring a plurality of delay time lengths of the video monitoring system to be detected when the video monitoring system to be detected performs image processing, and determining the average delay time length of the video monitoring system to be detected when the video monitoring system to be detected performs image processing based on the plurality of delay time lengths.

According to one example, the clock source of the physical timer is an active clock or a passive clock provided by a crystal with a stable oscillation period;

or the clock source of the physical timer is an active clock or a passive clock provided by the accurate time service equipment of the global positioning system GPS or the Beidou BD.

According to an example, the physical timer performs frequency locking through a phase-locked loop and a voltage-controlled oscillator, and counts and detects the output frequency signal through a counter, thereby outputting accurate time.

According to one example, after determining the delay time length of the video monitoring system to be detected in image processing based on the difference value between the second time stamp value and the first time stamp value, the method further includes:

acquiring historical data and equipment data of each video monitoring system in a plurality of video monitoring systems except the video monitoring system to be detected in the target area;

acquiring historical data and equipment data of the video monitoring system to be detected;

determining an adjustment parameter of the delay time length based on the historical data and the equipment data of the video monitoring system to be detected and the historical data and the equipment data of each video monitoring system in the target area except the video monitoring system to be detected; and

and determining an adjusted delay time length based on the adjustment parameter and the delay time length.

According to one example, the determining the adjustment parameter of the delay time length based on the historical data and the device data of the video monitoring system to be detected and the historical data and the device data of each video monitoring system of the plurality of video monitoring systems except the video monitoring system to be detected in the target area includes:

Acquiring delay time lengths and system load rates of the video monitoring system to be detected at a plurality of historical time points from the historical data of the video monitoring system to be detected, and determining a load adjustment coefficient of the video monitoring system to be detected according to the delay time lengths and the system load rates of the video monitoring system to be detected at the plurality of historical time points;

acquiring delay time lengths and system load rates of each video monitoring system in a plurality of video monitoring systems except the video monitoring system to be detected in the target area from historical data of each video monitoring system in the plurality of video monitoring systems except the video monitoring system to be detected in the target area, and determining a load adjustment coefficient of each video monitoring system according to the delay time lengths and the system load rates of each video monitoring system in the plurality of video monitoring systems except the video monitoring system to be detected in the target area in the plurality of historical time points;

determining a first adjustment coefficient of the video monitoring system to be detected based on the load adjustment coefficient of the video monitoring system to be detected and the load adjustment coefficient of each video monitoring system;

Acquiring processor information, network transmission information and data cache information of the video monitoring system to be detected from equipment data of the video monitoring system to be detected, and acquiring the processor information, the network transmission information and the data cache information of each video monitoring system from the equipment data of each video monitoring system except the video monitoring system to be detected in the target area;

determining a second adjustment coefficient of the video monitoring system to be detected based on the processor information, the network transmission information and the data cache information of the video monitoring system to be detected and the processor information, the network transmission information and the data cache information of each video monitoring system in the target area except the video monitoring system to be detected;

and determining an adjustment parameter of the delay time length of the video monitoring system to be detected based on the first adjustment coefficient and the second adjustment coefficient of the video monitoring system to be detected.

According to an example, determining a load adjustment factor of the video monitoring system to be detected according to a delay time length and a system load rate of the video monitoring system to be detected at a plurality of historical time points includes:

Determining a load adjustment coefficient of the video monitoring system to be detected based on the following formula:

DSL is the load adjusting coefficient of the video monitoring system to be detected;

the delay time length of the video monitoring system to be detected at the ith historical time point; />

For the system load rate of the video monitoring system to be detected at the ith historical time point,/>

For the maximum value of the system load rate of the video monitoring system to be detected at a plurality of historical time points, +.>

The method comprises the steps that the minimum value of system load rates of a video monitoring system to be detected at a plurality of historical time points is set; />

Is the first regulatory factor and->

；

Wherein i and->

Is natural number (i.e.)>

Is the number of historical time points of the video monitoring system to be detected.

According to an example, the determining the load adjustment coefficient of each video monitoring system according to the delay time length and the system load rate of each video monitoring system in a plurality of historical time points in the target area except the video monitoring system to be detected includes:

determining a load adjustment factor of each video monitoring system based on the following formula:

wherein ,

wherein ,

the load adjustment coefficient of the mth video monitoring system in the video monitoring systems is used; />

Is the firstThe delay time length of the m video monitoring systems at the nth historical time point; />

The system load rate of the mth video monitoring system at the nth historical time point is calculated; />

A second adjustment factor for the mth video surveillance system;

wherein n and->

Is natural number (i.e.)>

The number of historical time points of the mth video monitoring system;

wherein m and->

Is natural number (i.e.)>

And the number of the video monitoring systems except the video monitoring system to be detected in the target area is the number of the video monitoring systems except the video monitoring system to be detected in the target area.

According to one example, determining the first adjustment coefficient of the video monitoring system to be detected based on the load adjustment coefficient of the video monitoring system to be detected and the load adjustment coefficient of each video monitoring system includes:

；

wherein ,

video monitoring system for detectionAnd a second adjustment factor for the system.

According to one example, the determining the second adjustment coefficient of the video monitoring system to be detected based on the processor information, the network transmission information, and the data cache information of the video monitoring system to be detected, and the processor information, the network transmission information, and the data cache information of each of the plurality of video monitoring systems other than the video monitoring system to be detected in the target area includes:

Determining the number of processors of the video monitoring system to be detected and the number of cores of each processor according to the processor information of the video monitoring system to be detected, and determining the total number of cores of the video monitoring system to be detected based on the number of processors of the video monitoring system to be detected and the number of cores of each processor;

according to the network transmission information of the video monitoring system to be detected, determining the basic delay time for data transmission in the video monitoring system to be detected;

determining the cache capacity of the video monitoring system to be detected according to the data cache information of the video monitoring system to be detected;

determining the number of processors of each video monitoring system and the number of cores of each processor according to the processor information of each video monitoring system in the target area except the video monitoring system to be detected, and determining the total number of cores of each video monitoring system based on the number of processors of each video monitoring system and the number of cores of each processor;

according to the network transmission information of each video monitoring system, determining the basic delay time for data transmission in each video monitoring system;

Determining the cache capacity of each video monitoring system according to the data cache information of each video monitoring system;

and determining a second adjusting coefficient of the video monitoring system to be detected based on the total number of cores, the basic delay time and the buffer capacity of the video monitoring system to be detected and the total number of cores, the basic delay time and the buffer capacity of each video monitoring system.

According to one example, determining the second adjustment coefficient of the video surveillance system to be detected includes:

determining a second adjustment coefficient of the video monitoring system to be detected based on the following formula:

wherein ,

for a second adjustment factor of the video surveillance system to be detected,/->

For the total number of cores of the video surveillance system to be detected, < >>

Basic delay time for a video monitoring system to be tested +.>

The buffer capacity of the video monitoring system to be detected;

the total number of cores of the mth video monitoring system in a plurality of video monitoring systems except the video monitoring system to be detected in the target area is +.>

Foundation delay time for mth video monitoring system, < >>

The buffer capacity of the mth video monitoring system;

which is provided with M and->

Is natural number (i.e.)>

According to one example, the determining, based on the first adjustment coefficient and the second adjustment coefficient of the video monitoring system to be detected, an adjustment parameter of a delay time length of the video monitoring system to be detected includes:

determining an adjustment parameter of the delay time length of the video monitoring system to be detected based on the following formula:

wherein T is an adjustment parameter of delay time length of the video monitoring system to be detected,

。

according to one example, wherein determining the adjusted length of delay time based on the adjustment parameter and the length of delay time comprises:

the adjusted delay time length is determined based on the following formula:

wherein ,

for the adjusted delay time length, +.>

For the delay time length, T is an adjustment parameter of the delay time length.

According to another aspect of the present invention, there is provided a system for detecting a delay time of a video monitoring system, the system comprising:

the analyzing device is used for responding to the received delay time detection request from the user equipment, analyzing the delay time detection request to obtain a region identifier and a system identifier, determining a target region in a plurality of regions based on the region identifier, and determining a video monitoring system to be detected in a plurality of video monitoring systems in the target region based on the system identifier;

The setting device is used for setting the display area of the display device of the video monitoring system to be detected and the video acquisition scene of the video acquisition device of the video monitoring system to be detected in the image view-finding range of the image capturing device, wherein the video acquisition scene of the video acquisition device comprises a preset entity timer;

the video acquisition device is used for carrying out video acquisition on a video acquisition scene comprising the entity timer, and enabling a single-frame image comprising a first time mark value presented by the entity timer to exist in the acquired video;

the network transmission device is used for transmitting the acquired video to the display device;

a display device for displaying the video received via the network transmission device; and

the image grabbing device is used for determining a second time mark value presented by the entity timer at the same moment in the image view finding range when a single-frame image comprising the first time mark value appears in the video displayed by the display device; and determining the delay time length of the video monitoring system to be detected when performing image processing based on the difference value of the second time mark value and the first time mark value.

According to a further aspect of the present invention, there is provided a computer readable storage medium, characterized in that the storage medium stores a computer program for performing the method according to any of the above examples.

According to still another aspect of the present invention, there is provided an electronic apparatus including:

a processor;

a memory for storing the processor-executable instructions;

the processor is configured to read the executable instructions from the memory and execute the instructions to implement the method as described in any of the examples above.

According to still another aspect of the invention, a method and a system for rapidly detecting image delay of a camera device are provided, which belong to the technical field of video monitoring, and particularly aim at detecting delay of a video real-time monitoring or low-delay image monitoring system. The method comprises the following steps: adding a time mark into a video image through a time marking device, forming an image time stamp S1 from the time mark in the video image, displaying the video image and the image time stamp S1 through a display device, and acquiring the image time stamp S1 in the display device and the current time stamp S2 of the time marking device through a real-time video image of a snapshot device; the current time stamp S2 and the time stamp S1 are calculated to obtain the total delay time S of the video image from acquisition (camera) to transmission to display (display device), wherein S is the difference value between the time stamp S2 and the time stamp S1.

The method for rapidly detecting the image delay solves the technical problem of accurately measuring the delay time of the video monitoring system under the scenes of high real-time performance, low delay requirement of the monitoring video and the like of a user, and has the effects of simplicity, high efficiency and accuracy.

Drawings

Exemplary embodiments of the present invention may be more completely understood in consideration of the following drawings:

FIG. 1 is a flow chart of a method for detecting delay time of a video surveillance system according to an embodiment of the invention;

FIG. 2 is a schematic diagram of a synchronous acquisition system according to an embodiment of the present invention;

FIG. 3 is a schematic view of a time stamping device according to an embodiment of the present invention;

FIG. 4 is a flowchart of a delay time detection method according to another embodiment of the present invention;

fig. 5 is a schematic diagram of a system for detecting a delay time of a video monitoring system according to an embodiment of the present invention.

Detailed Description

Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. It should be apparent that the described embodiments are only some embodiments of the present invention and not all embodiments of the present invention, and it should be understood that the present invention is not limited by the example embodiments described herein.

It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise. It will be appreciated by those of skill in the art that the terms "first," "second," etc. in embodiments of the present invention are used merely to distinguish between different steps, devices or modules, etc., and do not represent any particular technical meaning nor necessarily logical order between them. It should also be understood that in embodiments of the present invention, "plurality" may refer to two or more, and "at least one" may refer to one, two or more.

It should also be appreciated that any component, data, or structure referred to in an embodiment of the invention may be generally understood as one or more without explicit limitation or the contrary in the context. In addition, the term "and/or" in the present invention is merely an association relationship describing the association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In the present invention, the character "/" generally indicates that the front and rear related objects are an or relationship. It should also be understood that the description of the embodiments of the present invention emphasizes the differences between the embodiments, and that the same or similar features may be referred to each other, and for brevity, will not be described in detail. Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description.

Fig. 1 is a flowchart of a method for detecting a delay time of a video monitoring system according to an embodiment of the present invention. The method comprises the following steps:

in step 101, in response to receiving a delay time detection request from a user equipment, the delay time detection request is parsed to obtain a region identifier and a system identifier, a target region is determined in a plurality of regions based on the region identifier, and a video monitoring system to be detected is determined in a plurality of video monitoring systems in the target region based on the system identifier.

In one embodiment, when it is desired to detect the delay time of a particular video surveillance system, it is necessary to determine a region identifier and a system identifier of the video surveillance system to be detected and generate a delay time detection request based on the region identifier and the system identifier. The user equipment requests to detect the delay time of the video monitoring system to be detected by sending a delay time detection request to a service platform or a service node. It should be appreciated that, in order to perform effective operation management on a plurality of video monitoring systems, the plurality of video monitoring systems are divided into a plurality of areas, and area identifiers are allocated to the video monitoring systems to identify or determine the areas where the video monitoring systems are located or are located. Preferably, multiple video surveillance systems may be included in each zone.

Step 102, setting the display area of the display device of the video monitoring system to be detected and the video acquisition scene of the video acquisition device of the video monitoring system to be detected in the image framing range of the image capturing device, wherein the video acquisition scene of the video acquisition device comprises a preset physical timer.

Fig. 2 is a schematic structural diagram of a synchronous acquisition system according to an embodiment of the present invention. As shown in fig. 2, the synchronous acquisition system includes: the device comprises a time mark generating device, an imaging device to be detected, a network transmission device, a display device and an image grabbing device. A time stamp generating device is arranged in the same space and time, the current space-time image containing the time stamp is recorded by using the image pickup device M to be detected, and the space-time image with the real-time stamp of the image pickup device M is recorded by using the image pickup device N (i.e. the image grabbing device) which is not to be detected.

In one example, the delay time of the image capturing apparatus M is determined as the absolute value of the difference between the time stamp S2 and the time stamp S1 from the current time stamp S2 shown by the time stamp generating apparatus in the image recorded by the image capturing apparatus N and the time stamp S1 included in the recorded image of the image capturing apparatus M. Preferably, the time stamp generating means is an accurate and recordable time generator or a fixed frequency counter. The time stamp generating means may mark the time variation in time-air by a value displayed by the frequency counter. Further, the time stamp generating device may be a similar device that reads the current time, such as a stopwatch, a clock, or the like.

In an example, the image capturing device and the network transmission device in the video monitoring system to be detected may be the tested object. This is because the processing time of the image pickup apparatus may cause delay, and the network transmission of the network transmission apparatus may also cause delay. It should be appreciated that the delay time of the video surveillance system to be detected may be a sum of the delay times of the individual components or devices. In addition, the display device is a display device of the video monitoring system, and is capable of displaying the image acquired by the image pickup device and directly displaying the update according to the screen refresh frequency. The image capturing device is a device capable of simultaneously recording an image or video on the display device and the time stamp generating device at the same time and in the same space. The image capturing device can be a camera, a mobile phone or a computer which can be used for image recording. And finally, the difference value of the two timestamps contained in the acquired display image is the image processing delay of the video monitoring system to be detected.

In one example, an image delay detection system for an image capture device, comprising: a time mark generating device, an image pickup device, a network transmission device, a display device and an image capturing device. The time stamp generating means are capable of generating a real-time stamp. The time stamp generating means may be means having a real-time display function capable of providing a time in space at which a current specific time is observable for forming a time stamp (e.g., a time stamp) in the image when the image is captured by the image capturing means. The image pickup device is used for picking up an image or video containing the display content of the time stamp generating device, and then the network transmission device transmits the image or video to the display device. The display device is used for displaying the acquired image. The display device displays the acquired image information, and the image information contains the system processing result of the imaging device to be detected. The image capturing means is for capturing again the scene image comprising both the display screen of the display means and the time stamp generating means to determine another time stamp, and calculating the image processing delay based on the time stamps obtained twice.

In one example, the image capturing device performs image recording again on the display device and the time stamp generating device under the same time-space. At this time, the current real-time timestamp S2 of the time stamp generating device and the timestamp S1 of the image before the recording of the image by the image-to-be-measured device displayed on the display device will be recorded. The image delay time S of the image capturing apparatus to be detected is the absolute value of the difference between the time stamp S1 and the time stamp S2. The time mark generating device is a fixed frequency generator, a counting display device or a clock. The image capturing device is a video recording apparatus having a storage capacity, such as a video camera, a mobile phone or a computer with a camera. The fixed frequency generator and the counting display device are counting display equipment for counting according to a certain frequency, the time between two counting values can be calculated through counting, and the clock is a stopwatch which can be accurate to milliseconds.

The image captured by the image capturing device comprises: a clock mark generating device and a real-time display device of the camera device to be detected in the same time space. And recording images and videos of the display devices of the clock mark generating device and the image pickup device to be detected. Furthermore, the image grabbing device can automatically grab, record and calculate the image according to the timing device or the timing pulse without manual work. It is thus seen that the image capturing device is capable of recording moving images of the display device and the physical timer at the same time and within the image viewing range. The image capturing device may be a camera, a video camera, a mobile phone capable of moving image capturing, or a personal computer capable of moving image capturing.

Fig. 3 is a schematic structural view of a time stamping device according to an embodiment of the present invention. As shown in fig. 3, the physical timer is an accurate recordable time generator or a fixed frequency counter. The clock source of the physical timer is an active clock or a passive clock provided by a crystal with a stable oscillation period; or the clock source of the physical timer is an active clock or a passive clock provided by the accurate time service equipment of the global positioning system GPS or the Beidou BD. The physical TIMER performs frequency locking through the phase-locked loop PLL (Phase lock loop) and the voltage-controlled oscillator, and counts the output frequency signal or outputs the time period through the TIMER counter, so that the accurate time is output. And obtaining the time corresponding to different frequencies by calculating the timing period. Furthermore, the counting of the periods with different frequencies can meet the numerical value acquisition requirements of different photoelectric counters, so that more accurate time is obtained.

Step 103, the video acquisition device acquires video of the video acquisition scene comprising the entity timer, and enables a single-frame image comprising the first time mark value presented by the entity timer to exist in the acquired video. Because the video acquisition device transmits the acquired video to the display device through the network transmission device and the acquired video is displayed by the display device, a certain time length is needed in the process, namely, the delay time of the video monitoring system. When a single frame image having a first time stamp value is displayed in the display device (for example, a single frame image having a first time stamp value in a displayed video or moving image), the time stamp at this time of the time stamp generating device is a second time stamp value because a certain time length has elapsed.

And 104, transmitting the acquired video to the display device through the network transmission device of the video monitoring system to be detected, so that the display device displays the video received through the network transmission device. As described above, when the display device displays the received video, the image capturing device determines the second time stamp value of the physical timer presented at the same time when the first time stamp value appears in the received video.

Step 105, when the video displayed by the display device appears a single frame image including the first time mark value, determining, by the image capturing device, a second time mark value presented by an entity timer in the image framing range at the same time. For example, the image capturing means is for capturing again the scene image including both the display screen of the display means and the time stamp generating means to determine another time stamp, and the image processing delay is calculated based on the time stamp obtained twice.

In one embodiment, when the video displayed by the display device appears a single frame image including the first time stamp value, determining, by the image capturing device, a second time stamp value presented by an entity timer in the image viewing range at the same time, including: when a single frame image including a first time mark value presented by the entity timer appears in a display area of the display device in a dynamic image recorded by the image capturing device, determining that the current time value of the entity timer is at the same moment and within an image framing range of the image capturing device; and determining the current time value of the entity timer as a second time mark value.

And step 106, determining the delay time length of the video monitoring system to be detected when performing image processing based on the difference value of the second time mark value and the first time mark value. For example, the current real-time timestamp S2 of the time stamp generating device and the timestamp S1 of the image before the recording of the image by the image-to-be-measured device displayed in the display device will be recorded. The image delay time S of the image capturing apparatus to be detected is the absolute value of the difference between the time stamp S1 and the time stamp S2.

In one embodiment, the method further includes respectively acquiring a plurality of delay time lengths of the video monitoring system to be detected when performing image processing, and determining an average delay time length of the video monitoring system to be detected when performing image processing based on the plurality of delay time lengths. For example, the previous detection steps are repeated, the time stamp in the image of the display device and the real-time stamp of the time marking device are obtained for a plurality of captured images, and the delay average value of the image capturing device is obtained after the difference value is calculated.

In one embodiment, after determining the delay time length of the video monitoring system to be detected in image processing based on the difference value between the second time stamp value and the first time stamp value, the method further includes: acquiring historical data and equipment data of each video monitoring system in a plurality of video monitoring systems except the video monitoring system to be detected in the target area; acquiring historical data and equipment data of the video monitoring system to be detected; determining an adjustment parameter of the delay time length based on the historical data and the equipment data of the video monitoring system to be detected and the historical data and the equipment data of each video monitoring system in the target area except the video monitoring system to be detected; and determining an adjusted delay time length based on the adjustment parameter and the delay time length.

In one embodiment, determining the adjustment parameter of the delay time length based on the historical data and the device data of the video monitoring system to be detected and the historical data and the device data of each video monitoring system of the plurality of video monitoring systems except the video monitoring system to be detected in the target area includes: acquiring delay time lengths and system load rates of the video monitoring system to be detected at a plurality of historical time points from the historical data of the video monitoring system to be detected, and determining a load adjustment coefficient of the video monitoring system to be detected according to the delay time lengths and the system load rates of the video monitoring system to be detected at the plurality of historical time points; acquiring delay time lengths and system load rates of each video monitoring system in a plurality of video monitoring systems except the video monitoring system to be detected in the target area from historical data of each video monitoring system in the plurality of video monitoring systems except the video monitoring system to be detected in the target area, and determining a load adjustment coefficient of each video monitoring system according to the delay time lengths and the system load rates of each video monitoring system in the plurality of video monitoring systems except the video monitoring system to be detected in the target area in the plurality of historical time points; determining a first adjustment coefficient of the video monitoring system to be detected based on the load adjustment coefficient of the video monitoring system to be detected and the load adjustment coefficient of each video monitoring system; acquiring processor information, network transmission information and data cache information of the video monitoring system to be detected from equipment data of the video monitoring system to be detected, and acquiring the processor information, the network transmission information and the data cache information of each video monitoring system from the equipment data of each video monitoring system except the video monitoring system to be detected in the target area; determining a second adjustment coefficient of the video monitoring system to be detected based on the processor information, the network transmission information and the data cache information of the video monitoring system to be detected and the processor information, the network transmission information and the data cache information of each video monitoring system in the target area except the video monitoring system to be detected; and determining an adjustment parameter of the delay time length of the video monitoring system to be detected based on the first adjustment coefficient and the second adjustment coefficient of the video monitoring system to be detected.

In one embodiment, determining the load adjustment factor of the video monitoring system to be detected according to the delay time lengths and the system load rates of the video monitoring system to be detected at a plurality of historical time points includes:

Is the first regulatory factor and->

；/>

Wherein i and->

Is natural number (i.e.)>

In one embodiment, determining the load adjustment coefficient of each video monitoring system according to the delay time length and the system load rate of each video monitoring system in a plurality of historical time points in the target area except the video monitoring system to be detected, includes:

wherein ,

wherein ,

The delay time length of the mth video monitoring system at the nth historical time point; />

A second adjustment factor for the mth video surveillance system;

wherein n and->

Is natural number (i.e.)>

The number of historical time points of the mth video monitoring system;

wherein m and->

Is natural number (i.e.)>

In one embodiment, determining the first adjustment coefficient of the video monitoring system to be detected based on the load adjustment coefficient of the video monitoring system to be detected and the load adjustment coefficient of each video monitoring system includes:

；

wherein ,

and the second adjustment coefficient is the second adjustment coefficient of the video monitoring system to be detected.

In one embodiment, determining the second adjustment coefficient of the video monitoring system to be detected based on the processor information, the network transmission information, and the data cache information of the video monitoring system to be detected, and the processor information, the network transmission information, and the data cache information of each of the plurality of video monitoring systems other than the video monitoring system to be detected in the target area includes: determining the number of processors of the video monitoring system to be detected and the number of cores of each processor according to the processor information of the video monitoring system to be detected, and determining the total number of cores of the video monitoring system to be detected based on the number of processors of the video monitoring system to be detected and the number of cores of each processor; according to the network transmission information of the video monitoring system to be detected, determining the basic delay time for data transmission in the video monitoring system to be detected; determining the cache capacity of the video monitoring system to be detected according to the data cache information of the video monitoring system to be detected; determining the number of processors of each video monitoring system and the number of cores of each processor according to the processor information of each video monitoring system in the target area except the video monitoring system to be detected, and determining the total number of cores of each video monitoring system based on the number of processors of each video monitoring system and the number of cores of each processor; according to the network transmission information of each video monitoring system, determining the basic delay time for data transmission in each video monitoring system; determining the cache capacity of each video monitoring system according to the data cache information of each video monitoring system; and determining a second adjusting coefficient of the video monitoring system to be detected based on the total number of cores, the basic delay time and the buffer capacity of the video monitoring system to be detected and the total number of cores, the basic delay time and the buffer capacity of each video monitoring system.

In one embodiment, determining the second adjustment factor of the video surveillance system to be detected includes:

wherein ,

Basic delay time for a video monitoring system to be tested +.>

The buffer capacity of the video monitoring system to be detected;

Foundation delay time for mth video monitoring system, < >>

The buffer capacity of the mth video monitoring system;

wherein m and->

Is natural number (i.e.)>

And the number of the video monitoring systems except the video monitoring system to be detected in the target area is the number of the video monitoring systems except the video monitoring system to be detected in the target area. />

In one embodiment, determining an adjustment parameter for a delay time length of the video monitoring system to be detected based on the first adjustment coefficient and the second adjustment coefficient of the video monitoring system to be detected includes: determining an adjustment parameter of the delay time length of the video monitoring system to be detected based on the following formula:

。

in one embodiment, determining the adjusted length of delay time based on the adjustment parameter and the length of delay time comprises: the adjusted delay time length is determined based on the following formula:

wherein ,

for the adjusted delay time length, +.>

Fig. 4 is a flowchart of a delay time detection method according to another embodiment of the present invention. As shown in fig. 4, the image capturing device and the image capturing device to be detected simultaneously capture, record or browse the images of the time stamp generating device. The image capturing device needs to capture the real-time display image of the image capturing device to be detected in the same picture besides the capture time stamp generating device, and the time stamp of the time stamp generating device is S2. And determining a timestamp S1 in the real-time display image, wherein the absolute value of the difference between S1 and S2 minus the refresh time of the display screen (the time of 60Hz display refresh rate is 16.67 ms) is the accurate time delay of the camera to be detected. The time mark transmitting device is composed of a clock accurate to millisecond or a countable frequency meter, the frequency meter can count freely according to the set size of the frequency, and the time is obtained by multiplying the count by the reciprocal of the frequency.

The image capturing device may manually determine the shooting time, or set the timing to shoot at a certain interval, or shoot or record by using an external triggering condition such as a frequency pulse. The captured image is automatically identified by using PyTouch software, and specifically, a one-stage target detection algorithm of a yolov5 network architecture is used for automatically identifying a time stamp in the image, so that the delay of the camera to be detected is obtained.

In one embodiment, the delay time detection method includes:

step 401, the time stamp generating device displays the time stamp in the acquired image by displaying the time stamp directly in front of the image capturing device through accurate time display or frequency counting, and the time stamp is S1;

step 402, displaying the image after passing through the image capturing device and the network transmission device in a display device, wherein the display image not only indicates the received image of the image capturing device which is already analyzed currently, but also comprises a time stamp S1 when the image is acquired;

in step 403, the image capturing device captures the latest time stamp of the time stamping device as S2, and the display time stamp captured by the image capturing device in the display device at the same time as S1, so that the delay of the image capturing system is S2-S1.

Fig. 5 is a schematic diagram of a system for detecting a delay time of a video monitoring system according to an embodiment of the present invention. As shown in fig. 5, the system 500 includes: the device comprises an analysis device 501, a setting device 502, a video acquisition device 503, a network transmission device 504, a display device 505 and an image grabbing device 506.

In one embodiment, the parsing means 501 is configured to parse the delay time detection request in response to receiving the delay time detection request from the user equipment, to obtain a region identifier and a system identifier, determine a target region in a plurality of regions based on the region identifier, and determine a video monitoring system to be detected in a plurality of video monitoring systems in the target region based on the system identifier.

In one embodiment, the setting device 502 is configured to set the display area of the display device of the video monitoring system to be detected and the video acquisition scene of the video acquisition device of the video monitoring system to be detected in the image framing range of the image capturing device, where the video acquisition scene of the video acquisition device includes a preset physical timer.

Preferably, the physical timer is an accurate recordable time generator or a fixed frequency counter. The image capturing device can record dynamic images of the display device and the physical timer at the same time and within the image framing range. The image capturing device is a camera, a video camera, a mobile phone capable of capturing moving images, or a personal computer capable of capturing moving images.

Preferably, the clock source of the physical timer is an active clock or a passive clock provided by a crystal with a stable oscillation period; or the clock source of the physical timer is an active clock or a passive clock provided by the accurate time service equipment of the global positioning system GPS or the Beidou BD. The physical timer realizes frequency locking through the phase-locked loop and the voltage-controlled oscillator, and counts and detects the output frequency signals through the counter, so that accurate time is output.

In one embodiment, the video capturing device 503 is configured to perform video capturing on a video capturing scene including the entity timer, and make a single frame image including a first time stamp value presented by the entity timer exist in the captured video.

In one embodiment, the network transmission device 504 is configured to transmit the acquired video to the display device 505.

In one embodiment, the display device 505 is configured to display video received via the network transmission device.

In one embodiment, the image capturing device 506 is configured to determine, when the video displayed by the display device appears in a single frame image including the first time stamp value, a second time stamp value that is presented by the physical timer at the same time in the framing range of the image; and determining the delay time length of the video monitoring system to be detected when performing image processing based on the difference value of the second time mark value and the first time mark value.

Preferably, when the video displayed by the display device appears a single frame image including the first time stamp value, determining, by the image capturing device, a second time stamp value presented by an entity timer in the image viewing range at the same time, including: when a single frame image including a first time mark value presented by the entity timer appears in a display area of the display device in a dynamic image recorded by the image capturing device, determining that the current time value of the entity timer is at the same moment and within an image framing range of the image capturing device; and determining the current time value of the entity timer as a second time mark value.

Preferably, the method further comprises the steps of respectively obtaining a plurality of delay time lengths of the video monitoring system to be detected when the video monitoring system to be detected performs image processing, and determining the average delay time length of the video monitoring system to be detected when the video monitoring system to be detected performs image processing based on the plurality of delay time lengths.

Preferably, after determining the delay time length of the video monitoring system to be detected in image processing based on the difference value between the second time stamp value and the first time stamp value, the method further includes: acquiring historical data and equipment data of each video monitoring system in a plurality of video monitoring systems except the video monitoring system to be detected in the target area; acquiring historical data and equipment data of the video monitoring system to be detected; determining an adjustment parameter of the delay time length based on the historical data and the equipment data of the video monitoring system to be detected and the historical data and the equipment data of each video monitoring system in the target area except the video monitoring system to be detected; and determining an adjusted delay time length based on the adjustment parameter and the delay time length.

Preferably, the determining the adjustment parameter of the delay time length based on the historical data and the equipment data of the video monitoring system to be detected and the historical data and the equipment data of each video monitoring system except the video monitoring system to be detected in the target area includes: acquiring delay time lengths and system load rates of the video monitoring system to be detected at a plurality of historical time points from the historical data of the video monitoring system to be detected, and determining a load adjustment coefficient of the video monitoring system to be detected according to the delay time lengths and the system load rates of the video monitoring system to be detected at the plurality of historical time points; acquiring delay time lengths and system load rates of each video monitoring system in a plurality of video monitoring systems except the video monitoring system to be detected in the target area from historical data of each video monitoring system in the plurality of video monitoring systems except the video monitoring system to be detected in the target area, and determining a load adjustment coefficient of each video monitoring system according to the delay time lengths and the system load rates of each video monitoring system in the plurality of video monitoring systems except the video monitoring system to be detected in the target area in the plurality of historical time points; determining a first adjustment coefficient of the video monitoring system to be detected based on the load adjustment coefficient of the video monitoring system to be detected and the load adjustment coefficient of each video monitoring system; acquiring processor information, network transmission information and data cache information of the video monitoring system to be detected from equipment data of the video monitoring system to be detected, and acquiring the processor information, the network transmission information and the data cache information of each video monitoring system from the equipment data of each video monitoring system except the video monitoring system to be detected in the target area; determining a second adjustment coefficient of the video monitoring system to be detected based on the processor information, the network transmission information and the data cache information of the video monitoring system to be detected and the processor information, the network transmission information and the data cache information of each video monitoring system in the target area except the video monitoring system to be detected; and determining an adjustment parameter of the delay time length of the video monitoring system to be detected based on the first adjustment coefficient and the second adjustment coefficient of the video monitoring system to be detected.

Preferably, the determining the load adjustment coefficient of the video monitoring system to be detected according to the delay time lengths and the system load rates of the video monitoring system to be detected at a plurality of historical time points includes:

Is the first regulatory factor and->

；

Wherein i and->

Is natural number (i.e.)>

Preferably, the determining the load adjustment coefficient of each video monitoring system according to the delay time length and the system load rate of each video monitoring system in a plurality of historical time points in the target area except the video monitoring system to be detected includes:

wherein ,

/>

wherein ,

A second adjustment factor for the mth video surveillance system;

wherein n and->

Is natural number (i.e.)>

The number of historical time points of the mth video monitoring system;

wherein m and->

Is natural number (i.e.)>

In addition to the video monitoring system to be detected in the target areaIs provided.

Preferably, the determining the first adjustment coefficient of the video monitoring system to be detected based on the load adjustment coefficient of the video monitoring system to be detected and the load adjustment coefficient of each video monitoring system includes:

；

wherein ,

Preferably, the determining the second adjustment coefficient of the video monitoring system to be detected based on the processor information, the network transmission information and the data cache information of the video monitoring system to be detected, and the processor information, the network transmission information and the data cache information of each video monitoring system in the plurality of video monitoring systems except the video monitoring system to be detected in the target area includes: determining the number of processors of the video monitoring system to be detected and the number of cores of each processor according to the processor information of the video monitoring system to be detected, and determining the total number of cores of the video monitoring system to be detected based on the number of processors of the video monitoring system to be detected and the number of cores of each processor; according to the network transmission information of the video monitoring system to be detected, determining the basic delay time for data transmission in the video monitoring system to be detected; determining the cache capacity of the video monitoring system to be detected according to the data cache information of the video monitoring system to be detected; determining the number of processors of each video monitoring system and the number of cores of each processor according to the processor information of each video monitoring system in the target area except the video monitoring system to be detected, and determining the total number of cores of each video monitoring system based on the number of processors of each video monitoring system and the number of cores of each processor; according to the network transmission information of each video monitoring system, determining the basic delay time for data transmission in each video monitoring system; determining the cache capacity of each video monitoring system according to the data cache information of each video monitoring system; and determining a second adjusting coefficient of the video monitoring system to be detected based on the total number of cores, the basic delay time and the buffer capacity of the video monitoring system to be detected and the total number of cores, the basic delay time and the buffer capacity of each video monitoring system.

Preferably, determining the second adjustment coefficient of the video monitoring system to be detected includes: determining a second adjustment coefficient of the video monitoring system to be detected based on the following formula:

wherein ,

Basic delay time for a video monitoring system to be tested +.>

The buffer capacity of the video monitoring system to be detected;

Is the mth viewBasic delay time of frequency monitoring system, +.>

The buffer capacity of the mth video monitoring system; />

Wherein m and->

Is natural number (i.e.)>

Preferably, the determining the adjustment parameter of the delay time length of the video monitoring system to be detected based on the first adjustment coefficient and the second adjustment coefficient of the video monitoring system to be detected includes:

。

preferably, wherein determining the adjusted delay time length based on the adjustment parameter and the delay time length comprises: the adjusted delay time length is determined based on the following formula:

wherein ,

for the adjusted delay time length, +.>

The methods and apparatus of the present application may be implemented in a number of ways. For example, the methods and apparatus of the present application may be implemented by software, hardware, firmware, or any combination of software, hardware, firmware. The above-described sequence of steps for the method is for illustration only, and the steps of the method of the present application are not limited to the sequence specifically described above unless specifically stated otherwise. Furthermore, in some embodiments, the present application may also be implemented as programs recorded in a recording medium, the programs including machine-readable instructions for implementing the methods according to the present application. Thus, the present application also covers a recording medium storing a program for executing the method according to the present application.

It is also noted that in the apparatus, devices and methods of the present application, the components or steps may be disassembled and/or assembled. Such decomposition and/or recombination should be considered as equivalent to the present application. The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the application. Thus, the present application is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for detecting a delay time of a video surveillance system, the method comprising:

2. The method of claim 1, wherein the physical timer is an accurate recordable time generator or a fixed frequency counter.

3. The method of claim 1, wherein the image capture device is capable of dynamic image recording of the display device and physical timer at the same time and within view of the image.

4. The method of claim 1, wherein the image capturing device is a camera, a video camera, a mobile phone capable of moving image capturing, or a personal computer capable of moving image capturing.

5. A method according to claim 3, wherein determining, by the image capture device, when a single frame image including the first time stamp value appears in the video displayed by the display device, a second time stamp value presented by an entity timer in the image view range at the same time, comprises:

6. The method of claim 1, further comprising separately obtaining a plurality of delay time lengths of the video surveillance system to be detected when performing image processing, and determining an average delay time length of the video surveillance system to be detected when performing image processing based on the plurality of delay time lengths.

7. The method of claim 1, wherein the clock source of the physical timer is an active clock or a passive clock provided by a crystal having a stable oscillation period;

8. The method according to claim 1 or 7, wherein the physical timer performs frequency locking through a phase-locked loop and a voltage-controlled oscillator, and the output frequency signal is counted and detected by a counter, thereby outputting the accurate time.

9. The method of claim 1, further comprising, after determining a length of delay time in image processing of the video surveillance system to be detected based on a difference between the second time stamp value and the first time stamp value:

10. The method of claim 9, wherein determining the adjustment parameter for the length of delay time based on the historical data and the device data of the video surveillance system to be detected and the historical data and the device data of each of the plurality of video surveillance systems other than the video surveillance system to be detected in the target area comprises:

11. The method of claim 10, wherein determining the load adjustment factor of the video surveillance system to be detected based on the system load factor and the length of delay time of the video surveillance system to be detected at a plurality of historical time points comprises:

For the maximum of the system load rates of the video surveillance system to be detected at a plurality of historical time points,

Is the first regulatory factor and->

；

Wherein i and->

Is natural number (i.e.)>

12. The method of claim 11, wherein determining the load adjustment factor for each video monitoring system of the plurality of video monitoring systems in the target area, except the video monitoring system to be detected, based on the delay time lengths and the system load rates of each video monitoring system at a plurality of historical time points, comprises:

wherein ,

wherein ,

A second adjustment factor for the mth video surveillance system;

wherein n and->

Is natural number (i.e.)>

The number of historical time points of the mth video monitoring system;

wherein m and->

Is natural number (i.e.)>

13. The method of claim 12, wherein determining the first adjustment factor for the video surveillance system to be detected based on the load adjustment factors for the video surveillance system to be detected and the load adjustment factors for each video surveillance system comprises:

；

wherein ,

14. The method of claim 13, wherein determining the second adjustment factor for the video surveillance system to be detected based on the processor information, the network transmission information, and the data cache information for the video surveillance system to be detected, and the processor information, the network transmission information, and the data cache information for each of the plurality of video surveillance systems within the target area other than the video surveillance system to be detected, comprises:

15. The method of claim 14, wherein determining a second adjustment factor for the video surveillance system to be detected comprises:

wherein ,

Basic delay time for a video monitoring system to be tested +.>

The buffer capacity of the video monitoring system to be detected;

Foundation delay time for mth video monitoring system, < >>

The buffer capacity of the mth video monitoring system;

Wherein m and->

Is natural number (i.e.)>

16. The method of claim 15, wherein determining an adjustment parameter for a delay time length of the video surveillance system to be detected based on the first adjustment coefficient and the second adjustment coefficient of the video surveillance system to be detected comprises:

/>

。

17. the method of claim 9, wherein determining the adjusted length of delay time based on the adjustment parameter and the length of delay time comprises:

the adjusted delay time length is determined based on the following formula:

wherein ,

for the adjusted delay time length, +.>

For extendingThe delay time length, T, is the adjustment parameter of the delay time length.

18. A system for detecting a delay time of a video surveillance system, the system comprising:

19. A computer readable storage medium, characterized in that the storage medium stores a computer program for executing the method of any one of claims 1-17.

20. An electronic device, comprising:

a processor;

a memory for storing the processor-executable instructions;

the processor is configured to read the executable instructions from the memory and execute the instructions to implement the method of any one of claims 1-17.